It is known that esophagogastroduodenoscopy is currently the main diagnostic technique for pathologies of the upper digestive tract: it also allows to obtain biopsy specimens for possible complementary tests.
While providing excellent macroscopic visualization of the explored viscera, endoscopy alone does not achieve a satisfactory diagnostic sensitivity, since several pathologies do not produce macroscopically detectable changes in the affected organs.
Pathologies frequently associated with normal endoscopic findings are infection with Helicobacter pylori (H. pylori) and fundal atrophic gastritis. Both conditions are important from the clinical and pathological standpoint: the former (H. pylori infection) because in addition to being widespread in the general population (20-90%) it is involved in determining the pathogenesis of many gastroduodenal disorders (ulcer, gastritis, lymphoma, et cetera), and the latter (atrophic gastritis) because it is a neoplastic risk factor.
In order to increase diagnostic possibilities, endoscopy is usually complemented by complementary tests performed on biopsy samples taken during endoscopy. These tests are usually the urease test and histological examination.
Actually, performing these tests does not provide full protection against possible diagnostic errors or omissions. The spot distribution of these pathologies can in fact cause falsely negative results due to the fact that the biopsy samples were taken in areas not affected by the disease. Moreover, falsely positive results are also possible.
The problem worsens if one considers that a substantial percentage of patients subjected to endoscopy is found to have neither H. pylori infection nor histological evidence of simple or atrophic gastritis. For these patients, performing the complementary tests leads to an unnecessary increase of the duration of the test (and therefore to greater invasiveness), to consumption of materials (biopsy forceps, test tubes, et cetera) and most of all to a considerable financial expenditure.
The problem could be solved if one could, in some way, predict atrophy and H. pylori-status in individuals with normal endoscopic findings. In this manner, complementary diagnostic tests would be performed only in patients who are potentially affected by these pathologies and would be avoided in the others. Such a prediction might also allow a better and more suitable biopsy screening program (with many biopsy samples in the areas most at risk), so as to greatly contain the problem of lesion focality.